If a circuit has to be interfaced to a computer, the interface that is most likely to be used is a USB interface. If it is wireless, either a wireless USB or a Bluetooth LE type interface. Among the two of these, the USB interface is simpler. We have decided to use it in some of our products for analog and wirelss applications.
It is interesting that the simplest USB interface that can be used is a fixed function Human Interface Device interface or HID. This does not require extensive effort to program drivers or other complicated software. The snag is however, that the data transfer rate is somewhat limited to about 64 KBS.
Getting information about HID devices and tutorials for the newbie is really quite difficult, and it seems that USB interfacing is a bit of a black art. We are currently building USB interfaces using HID technology for a USB to SPI bridge application.
The SPI format is used in a programmable RF amplifier for control. The other side is of course the computer. Measurement data of the gain of the amplifier is also interfaced to the USB port. Our intent is to share our experience and design information to all. Keep tuned if interested.
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Please contact Signal Processing Group Inc. on email: spg@signalpro.biz . We will answer within 24 hours.
Please see details at http://www.signalpro.biz/2rf_amplifier_details.htm Delivery lead time is 3 days. Return within 30 days for a full refund. Price is $15.00 for one unit and $10.00 per unit in volumes of 100. For higher volumes than 100 please contact Signal Processing group Inc.
Delivery lead time is 3 days. Return within 30 days for a full refund. Price is $15.00 for one unit and $12.00 per unit in volumes of 100. For higher volumes than 100 please contact Signal Processing Group Inc. at email: spg@signalpro.biz or call 602-626-0272 for fastest service.
The input interface.
The frequency divider has a differential analog interface. The following parameters apply:
The minimum frequency that can be input is 500 Mhz and the maximum frequency is 6.0 Ghz.
The RF input level is 5 dBm to – 5 dBm. For lower frequencies make sure that the slew rate is
greater than 560 V/us. The input is biased by two 500 Ohm resistors connected to a 1.6V DC bias.
Therefore AC coupling is used at the input. These are two 100pF capacitors.
The output interface.
The output is single ended. The output driver is capable of sourcing and sinking 24 mA. The
equivalent output impedance is 50 Ohm. To avoid reflections it is recommended that the divider
work into a 50 Ohm load.
General operation.
The inputs are applied to the input SMA I/O. The product will work with both a differential input as
well as a single ended input. However, a differential input works best. The division ratio is applied
to the N1 and N2 control inputs as follows:
N2 N1 Division ratio
0 0 8
0 1 16
1 0 32
1 1 64
The logic levels are:
Logic level Voltage
1 1.4V minimum
0 0.6V maximum
The supply voltage interface.
The operating supply voltage is 3.3V typical. The quiescent (DC) operating supply current is 2 mA.
Please contact Signal Processing Group Inc. at email: spg@signalpro.biz or telephone 602-626-0272. Get a response within minutes or worst case 24 hours if contact is by email.
RF Switch typical features
Supply voltage = Vcc = 0/+5 Vdc
Operatng temperature = TA = -50° C to 125 Deg C
Operating impedance = 50 Ohm
Input power for 1 dB
compression ( 5.0V system) = 37 dBm ( f = 0.5 to 3 Ghz)
Input third order Intercept = 64 dBm ( 0 to 5.0V system, f = 0.5 to 3 Ghz)
Operating frequency range = DC to 3 Ghz.
Insertion loss DC to 3 Ghz = 0.8 dB
Isolation DC to 3 Ghz = 14 dB minimum
Return loss DC to 3 Ghz = 20 dB
50% contl to 10/90 %
( ON/OFF) = 120 ns
Summary Specifications
Gain, Operating: 19.5 dB
Operating frequency range: 1.0 – 2700 Mhz
OIP3: (Pout = 19.0 dBm), -8.5 dBm
P1dB: 4.6 dBm
N.F: 4.2 dB
Supply voltage Operating: 3.3 – 5.5 Volts
Price: single unit $7.50, 100 units : $5:50.
Free delivery, shipping lead time 2 days.
30 day return policy, buyer ships.
Supply current Supply = 5.0V, 23.0 mA
Signal Processing Group Inc. is offering embedded design and development using Microchip processors. Please contact us on spg@signalpro.biz for more information